import React, { Component } from "react";

class Header extends Component {
  render() {
    return (
      <div>Header</div>
    )
  }
}

class List extends Component{
  render(){
    return (
      <ul>
        <li>111</li>
        <li>222</li>
        <li>333</li>
      </ul>
    )
  }
}

class Main extends Component {
  render() {
    return (
      <div>
        <h1>Main</h1>
        <List></List>
      </div>
    )
  }
}

class Footer extends Component {
  render() {
    return (
      <div>Footer</div>
    )
  }
}




export default class App extends Component {
  render() {
    return (
      <div>
        <Header></Header>
        <Main></Main>
        <Footer></Footer>
      </div>
    );
  }
}
 